Direct writing of polymer thick film resistors using a novel laser transfer technique

Polymer thick film (PTF) resistors were fabricated using a new laser-based transfer technique called matrix-assisted pulsed laser evaporation direct w rite (MAPLE-DW). MAPLE-DW is a versatile direct writing technique capable o f writing a wide variety of materials on virtually any substrate in air and at room temperature. Epoxy-based PTF resistors spanning four decades of sh eet resistances (10 Omega /sq. to 100 k Omega /sq.) were deposited on alumi na substrates under ambient conditions. Electrical characteristics or these MAPLE-DW deposited resistors were studied at a wide frequency range (I MHz to 1.8 GHz), and the results were explained through an equivalent circuit model and impedance spectroscopy. Temperature coefficient of resistance mea surements for the PTF resistors were performed between 25 and 125 degreesC. The results based on the percolation theory were used to explain the tempe rature dependence of the resistance behavior of the PTF resistors.